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<table width="100%" summary="page for Theoph"><tr><td>Theoph</td><td style="text-align: right;">R Documentation</td></tr></table>

<h2>Pharmacokinetics of Theophylline</h2>

<h3>Description</h3>

<p>The <code>Theoph</code> data frame has 132 rows and 5 columns of data from
an experiment on the pharmacokinetics of theophylline.</p>


<h3>Usage</h3>

<pre>Theoph</pre>


<h3>Format</h3>

<p>An object of class
<code>c("nfnGroupedData", "nfGroupedData", "groupedData", "data.frame")</code>
containing the following columns:
</p>

<dl>
<dt>Subject</dt><dd>
<p>an ordered factor with levels <code>1</code>, ..., <code>12</code>
identifying the subject on whom the observation was made.  The
ordering is by increasing maximum concentration of theophylline
observed.
</p>
</dd>
<dt>Wt</dt><dd>
<p>weight of the subject (kg).
</p>
</dd>
<dt>Dose</dt><dd>
<p>dose of theophylline administered orally to the subject (mg/kg).
</p>
</dd>
<dt>Time</dt><dd>
<p>time since drug administration when the sample was drawn (hr).
</p>
</dd>
<dt>conc</dt><dd>
<p>theophylline concentration in the sample (mg/L).
</p>
</dd>
</dl>



<h3>Details</h3>

<p>Boeckmann, Sheiner and Beal (1994) report data from a study by
Dr. Robert Upton of the kinetics of the anti-asthmatic drug
theophylline.  Twelve subjects were given oral doses of theophylline
then serum concentrations were measured at 11 time points over the
next 25 hours.
</p>
<p>These data are analyzed in Davidian and Giltinan (1995) and Pinheiro
and Bates (2000) using a two-compartment open pharmacokinetic model,
for which a self-starting model function, <code>SSfol</code>, is available.
</p>
<p>This dataset was originally part of package <code>nlme</code>, and that has
methods (including for <code>[</code>, <code>as.data.frame</code>, <code>plot</code> and
<code>print</code>) for its grouped-data classes.
</p>


<h3>Source</h3>

<p>Boeckmann, A. J., Sheiner, L. B. and Beal, S. L. (1994), <em>NONMEM
Users Guide: Part V</em>, NONMEM Project Group, University of
California, San Francisco.
</p>
<p>Davidian, M. and Giltinan, D. M. (1995)
<em>Nonlinear Models for Repeated Measurement Data</em>,
Chapman &amp; Hall
(section 5.5, p. 145 and section 6.6, p. 176)
</p>
<p>Pinheiro, J. C. and Bates, D. M. (2000) <em>Mixed-effects Models in
S and S-PLUS</em>, Springer (Appendix A.29)
</p>


<h3>See Also</h3>

<p><code>SSfol</code></p>


<h3>Examples</h3>

<pre>
require(stats); require(graphics)

coplot(conc ~ Time | Subject, data = Theoph, show.given = FALSE)
Theoph.4 &lt;- subset(Theoph, Subject == 4)
fm1 &lt;- nls(conc ~ SSfol(Dose, Time, lKe, lKa, lCl),
           data = Theoph.4)
summary(fm1)
plot(conc ~ Time, data = Theoph.4,
     xlab = "Time since drug administration (hr)",
     ylab = "Theophylline concentration (mg/L)",
     main = "Observed concentrations and fitted model",
     sub  = "Theophylline data - Subject 4 only",
     las = 1, col = 4)
xvals &lt;- seq(0, par("usr")[2], length.out = 55)
lines(xvals, predict(fm1, newdata = list(Time = xvals)),
      col = 4)
</pre>


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